We all know that it's up to you to push yourself when you exercise, and the sort of machine you use to do your cardio with doesn't necessarily predetermine the level of intensity of your workout.
What is your favourite cardio machine? This can be the one you use most often, enjoy the most (if you do like exercise ) or feel is the most challenging.
I'll start off: I love the exercise bike and rower but right now I'm in a big treadmill phase. My knees are taking a beating from sprint intervals and uphill jogging but I've never felt this fit in my life!
How about you?